1. Field of the Invention
The present invention generally involves the field of technology pertaining to devices for the hypodermic injection of medications into a human or animal patient. More particularly, the invention relates to an improved shield assembly for hypodermic injection devices provide with an automatically engageable shield member for preventing reuse of such devices.
2. Description of the Prior Art
Devices for injecting a medication into the body of a human or animal patient are well known. Such devices include hypodermic syringes which receive a quantity of the medication to be injected from an ampoule, and intravenous needles which are inserted into the patient for continuous administration of a treatment substance from a supply container under gravitational flow. Because these devices utilize injection needles, they are generally of a disposable nature and therefore discarded after a single use. It is important that an individual responsible for the safe disposition of the discarded devices be protected from the sharp ends of the needles so that inadvertent injury will not occur. This is particularly critical when the needles have been applied to patients capable of contaminating the needles with blood-transmitted diseases, such as hepatitis or aquired immune deficiency syndrome. It is further important that such hypodermic devices be prevented from being reused by unauthorized individuals.
It is known to provide a hypodermic needle with a cover or shield for preventing inadvertent injury caused by the sharp end of the needle, reuse of the needle or contamination of the needle. These known devices typically require manual removal or replacement and, in some cases, manual adjustment for their disposition either before or after application of the hypodermic needle.